path: root/contrib/libs/cxxsupp/libcxx/include/__tree

// -*- C++ -*- 
//===----------------------------------------------------------------------===// 
// 
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// 
//===----------------------------------------------------------------------===// 
 
#ifndef _LIBCPP___TREE 
#define _LIBCPP___TREE 
 
#include <__config> 
#include <__utility/forward.h> 
#include <algorithm> 
#include <iterator> 
#include <limits> 
#include <memory> 
#include <stdexcept> 
 
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 
#pragma GCC system_header 
#endif 
 
_LIBCPP_PUSH_MACROS 
#include <__undef_macros> 
 
 
_LIBCPP_BEGIN_NAMESPACE_STD 
 
#if defined(__GNUC__) && !defined(__clang__) // gcc.gnu.org/PR37804
template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS map;
template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS multimap;
template <class, class, class> class _LIBCPP_TEMPLATE_VIS set;
template <class, class, class> class _LIBCPP_TEMPLATE_VIS multiset;
#endif

template <class _Tp, class _Compare, class _Allocator> class __tree; 
template <class _Tp, class _NodePtr, class _DiffType> 
    class _LIBCPP_TEMPLATE_VIS __tree_iterator; 
template <class _Tp, class _ConstNodePtr, class _DiffType> 
    class _LIBCPP_TEMPLATE_VIS __tree_const_iterator; 
 
template <class _Pointer> class __tree_end_node; 
template <class _VoidPtr> class __tree_node_base; 
template <class _Tp, class _VoidPtr> class __tree_node; 
 
template <class _Key, class _Value> 
struct __value_type; 
 
template <class _Allocator> class __map_node_destructor; 
template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_iterator; 
template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_const_iterator; 
 
/* 
 
_NodePtr algorithms 
 
The algorithms taking _NodePtr are red black tree algorithms.  Those 
algorithms taking a parameter named __root should assume that __root 
points to a proper red black tree (unless otherwise specified). 
 
Each algorithm herein assumes that __root->__parent_ points to a non-null 
structure which has a member __left_ which points back to __root.  No other 
member is read or written to at __root->__parent_. 
 
__root->__parent_ will be referred to below (in comments only) as end_node. 
end_node->__left_ is an externably accessible lvalue for __root, and can be 
changed by node insertion and removal (without explicit reference to end_node). 
 
All nodes (with the exception of end_node), even the node referred to as 
__root, have a non-null __parent_ field. 
 
*/ 
 
// Returns:  true if __x is a left child of its parent, else false 
// Precondition:  __x != nullptr. 
template <class _NodePtr> 
inline _LIBCPP_INLINE_VISIBILITY 
bool 
__tree_is_left_child(_NodePtr __x) _NOEXCEPT 
{ 
    return __x == __x->__parent_->__left_; 
} 
 
// Determines if the subtree rooted at __x is a proper red black subtree.  If 
//    __x is a proper subtree, returns the black height (null counts as 1).  If 
//    __x is an improper subtree, returns 0. 
template <class _NodePtr> 
unsigned 
__tree_sub_invariant(_NodePtr __x) 
{ 
    if (__x == nullptr) 
        return 1; 
    // parent consistency checked by caller 
    // check __x->__left_ consistency 
    if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x) 
        return 0; 
    // check __x->__right_ consistency 
    if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x) 
        return 0; 
    // check __x->__left_ != __x->__right_ unless both are nullptr 
    if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr) 
        return 0; 
    // If this is red, neither child can be red 
    if (!__x->__is_black_) 
    { 
        if (__x->__left_ && !__x->__left_->__is_black_) 
            return 0; 
        if (__x->__right_ && !__x->__right_->__is_black_) 
            return 0; 
    } 
    unsigned __h = _VSTD::__tree_sub_invariant(__x->__left_); 
    if (__h == 0) 
        return 0;  // invalid left subtree 
    if (__h != _VSTD::__tree_sub_invariant(__x->__right_)) 
        return 0;  // invalid or different height right subtree 
    return __h + __x->__is_black_;  // return black height of this node 
} 
 
// Determines if the red black tree rooted at __root is a proper red black tree. 
//    __root == nullptr is a proper tree.  Returns true is __root is a proper 
//    red black tree, else returns false. 
template <class _NodePtr> 
bool 
__tree_invariant(_NodePtr __root) 
{ 
    if (__root == nullptr) 
        return true; 
    // check __x->__parent_ consistency 
    if (__root->__parent_ == nullptr) 
        return false; 
    if (!_VSTD::__tree_is_left_child(__root)) 
        return false; 
    // root must be black 
    if (!__root->__is_black_) 
        return false; 
    // do normal node checks 
    return _VSTD::__tree_sub_invariant(__root) != 0; 
} 
 
// Returns:  pointer to the left-most node under __x. 
// Precondition:  __x != nullptr. 
template <class _NodePtr> 
inline _LIBCPP_INLINE_VISIBILITY 
_NodePtr 
__tree_min(_NodePtr __x) _NOEXCEPT 
{ 
    while (__x->__left_ != nullptr) 
        __x = __x->__left_; 
    return __x; 
} 
 
// Returns:  pointer to the right-most node under __x. 
// Precondition:  __x != nullptr. 
template <class _NodePtr> 
inline _LIBCPP_INLINE_VISIBILITY 
_NodePtr 
__tree_max(_NodePtr __x) _NOEXCEPT 
{ 
    while (__x->__right_ != nullptr) 
        __x = __x->__right_; 
    return __x; 
} 
 
// Returns:  pointer to the next in-order node after __x. 
// Precondition:  __x != nullptr. 
template <class _NodePtr> 
_NodePtr 
__tree_next(_NodePtr __x) _NOEXCEPT 
{ 
    if (__x->__right_ != nullptr) 
        return _VSTD::__tree_min(__x->__right_); 
    while (!_VSTD::__tree_is_left_child(__x)) 
        __x = __x->__parent_unsafe(); 
    return __x->__parent_unsafe(); 
} 
 
template <class _EndNodePtr, class _NodePtr> 
inline _LIBCPP_INLINE_VISIBILITY 
_EndNodePtr 
__tree_next_iter(_NodePtr __x) _NOEXCEPT 
{ 
    if (__x->__right_ != nullptr) 
        return static_cast<_EndNodePtr>(_VSTD::__tree_min(__x->__right_)); 
    while (!_VSTD::__tree_is_left_child(__x)) 
        __x = __x->__parent_unsafe(); 
    return static_cast<_EndNodePtr>(__x->__parent_); 
} 
 
// Returns:  pointer to the previous in-order node before __x. 
// Precondition:  __x != nullptr. 
// Note: __x may be the end node. 
template <class _NodePtr, class _EndNodePtr> 
inline _LIBCPP_INLINE_VISIBILITY 
_NodePtr 
__tree_prev_iter(_EndNodePtr __x) _NOEXCEPT 
{ 
    if (__x->__left_ != nullptr) 
        return _VSTD::__tree_max(__x->__left_); 
    _NodePtr __xx = static_cast<_NodePtr>(__x); 
    while (_VSTD::__tree_is_left_child(__xx)) 
        __xx = __xx->__parent_unsafe(); 
    return __xx->__parent_unsafe(); 
} 
 
// Returns:  pointer to a node which has no children 
// Precondition:  __x != nullptr. 
template <class _NodePtr> 
_NodePtr 
__tree_leaf(_NodePtr __x) _NOEXCEPT 
{ 
    while (true) 
    { 
        if (__x->__left_ != nullptr) 
        { 
            __x = __x->__left_; 
            continue; 
        } 
        if (__x->__right_ != nullptr) 
        { 
            __x = __x->__right_; 
            continue; 
        } 
        break; 
    } 
    return __x; 
} 
 
// Effects:  Makes __x->__right_ the subtree root with __x as its left child 
//           while preserving in-order order. 
// Precondition:  __x->__right_ != nullptr 
template <class _NodePtr> 
void 
__tree_left_rotate(_NodePtr __x) _NOEXCEPT 
{ 
    _NodePtr __y = __x->__right_; 
    __x->__right_ = __y->__left_; 
    if (__x->__right_ != nullptr) 
        __x->__right_->__set_parent(__x); 
    __y->__parent_ = __x->__parent_; 
    if (_VSTD::__tree_is_left_child(__x)) 
        __x->__parent_->__left_ = __y; 
    else 
        __x->__parent_unsafe()->__right_ = __y; 
    __y->__left_ = __x; 
    __x->__set_parent(__y); 
} 
 
// Effects:  Makes __x->__left_ the subtree root with __x as its right child 
//           while preserving in-order order. 
// Precondition:  __x->__left_ != nullptr 
template <class _NodePtr> 
void 
__tree_right_rotate(_NodePtr __x) _NOEXCEPT 
{ 
    _NodePtr __y = __x->__left_; 
    __x->__left_ = __y->__right_; 
    if (__x->__left_ != nullptr) 
        __x->__left_->__set_parent(__x); 
    __y->__parent_ = __x->__parent_; 
    if (_VSTD::__tree_is_left_child(__x)) 
        __x->__parent_->__left_ = __y; 
    else 
        __x->__parent_unsafe()->__right_ = __y; 
    __y->__right_ = __x; 
    __x->__set_parent(__y); 
} 
 
// Effects:  Rebalances __root after attaching __x to a leaf. 
// Precondition:  __root != nulptr && __x != nullptr. 
//                __x has no children. 
//                __x == __root or == a direct or indirect child of __root. 
//                If __x were to be unlinked from __root (setting __root to 
//                  nullptr if __root == __x), __tree_invariant(__root) == true. 
// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_ 
//                may be different than the value passed in as __root. 
template <class _NodePtr> 
void 
__tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT 
{ 
    __x->__is_black_ = __x == __root; 
    while (__x != __root && !__x->__parent_unsafe()->__is_black_) 
    { 
        // __x->__parent_ != __root because __x->__parent_->__is_black == false 
        if (_VSTD::__tree_is_left_child(__x->__parent_unsafe())) 
        { 
            _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_; 
            if (__y != nullptr && !__y->__is_black_) 
            { 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = true; 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = __x == __root; 
                __y->__is_black_ = true; 
            } 
            else 
            { 
                if (!_VSTD::__tree_is_left_child(__x)) 
                { 
                    __x = __x->__parent_unsafe(); 
                    _VSTD::__tree_left_rotate(__x); 
                } 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = true; 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = false; 
                _VSTD::__tree_right_rotate(__x); 
                break; 
            } 
        } 
        else 
        { 
            _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_; 
            if (__y != nullptr && !__y->__is_black_) 
            { 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = true; 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = __x == __root; 
                __y->__is_black_ = true; 
            } 
            else 
            { 
                if (_VSTD::__tree_is_left_child(__x)) 
                { 
                    __x = __x->__parent_unsafe(); 
                    _VSTD::__tree_right_rotate(__x); 
                } 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = true; 
                __x = __x->__parent_unsafe(); 
                __x->__is_black_ = false; 
                _VSTD::__tree_left_rotate(__x); 
                break; 
            } 
        } 
    } 
} 
 
// Precondition:  __root != nullptr && __z != nullptr. 
//                __tree_invariant(__root) == true. 
//                __z == __root or == a direct or indirect child of __root. 
// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed. 
// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_ 
//                nor any of its children refer to __z.  end_node->__left_ 
//                may be different than the value passed in as __root. 
template <class _NodePtr> 
void 
__tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT 
{ 
    // __z will be removed from the tree.  Client still needs to destruct/deallocate it 
    // __y is either __z, or if __z has two children, __tree_next(__z). 
    // __y will have at most one child. 
    // __y will be the initial hole in the tree (make the hole at a leaf) 
    _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ? 
                    __z : _VSTD::__tree_next(__z); 
    // __x is __y's possibly null single child 
    _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_; 
    // __w is __x's possibly null uncle (will become __x's sibling) 
    _NodePtr __w = nullptr; 
    // link __x to __y's parent, and find __w 
    if (__x != nullptr) 
        __x->__parent_ = __y->__parent_; 
    if (_VSTD::__tree_is_left_child(__y)) 
    { 
        __y->__parent_->__left_ = __x; 
        if (__y != __root) 
            __w = __y->__parent_unsafe()->__right_; 
        else 
            __root = __x;  // __w == nullptr 
    } 
    else 
    { 
        __y->__parent_unsafe()->__right_ = __x; 
        // __y can't be root if it is a right child 
        __w = __y->__parent_->__left_; 
    } 
    bool __removed_black = __y->__is_black_; 
    // If we didn't remove __z, do so now by splicing in __y for __z, 
    //    but copy __z's color.  This does not impact __x or __w. 
    if (__y != __z) 
    { 
        // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr 
        __y->__parent_ = __z->__parent_; 
        if (_VSTD::__tree_is_left_child(__z)) 
            __y->__parent_->__left_ = __y; 
        else 
            __y->__parent_unsafe()->__right_ = __y; 
        __y->__left_ = __z->__left_; 
        __y->__left_->__set_parent(__y); 
        __y->__right_ = __z->__right_; 
        if (__y->__right_ != nullptr) 
            __y->__right_->__set_parent(__y); 
        __y->__is_black_ = __z->__is_black_; 
        if (__root == __z) 
            __root = __y; 
    } 
    // There is no need to rebalance if we removed a red, or if we removed 
    //     the last node. 
    if (__removed_black && __root != nullptr) 
    { 
        // Rebalance: 
        // __x has an implicit black color (transferred from the removed __y) 
        //    associated with it, no matter what its color is. 
        // If __x is __root (in which case it can't be null), it is supposed 
        //    to be black anyway, and if it is doubly black, then the double 
        //    can just be ignored. 
        // If __x is red (in which case it can't be null), then it can absorb 
        //    the implicit black just by setting its color to black. 
        // Since __y was black and only had one child (which __x points to), __x 
        //   is either red with no children, else null, otherwise __y would have 
        //   different black heights under left and right pointers. 
        // if (__x == __root || __x != nullptr && !__x->__is_black_) 
        if (__x != nullptr) 
            __x->__is_black_ = true; 
        else 
        { 
            //  Else __x isn't root, and is "doubly black", even though it may 
            //     be null.  __w can not be null here, else the parent would 
            //     see a black height >= 2 on the __x side and a black height 
            //     of 1 on the __w side (__w must be a non-null black or a red 
            //     with a non-null black child). 
            while (true) 
            { 
                if (!_VSTD::__tree_is_left_child(__w))  // if x is left child 
                { 
                    if (!__w->__is_black_) 
                    { 
                        __w->__is_black_ = true; 
                        __w->__parent_unsafe()->__is_black_ = false; 
                        _VSTD::__tree_left_rotate(__w->__parent_unsafe()); 
                        // __x is still valid 
                        // reset __root only if necessary 
                        if (__root == __w->__left_) 
                            __root = __w; 
                        // reset sibling, and it still can't be null 
                        __w = __w->__left_->__right_; 
                    } 
                    // __w->__is_black_ is now true, __w may have null children 
                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) && 
                        (__w->__right_ == nullptr || __w->__right_->__is_black_)) 
                    { 
                        __w->__is_black_ = false; 
                        __x = __w->__parent_unsafe(); 
                        // __x can no longer be null 
                        if (__x == __root || !__x->__is_black_) 
                        { 
                            __x->__is_black_ = true; 
                            break; 
                        } 
                        // reset sibling, and it still can't be null 
                        __w = _VSTD::__tree_is_left_child(__x) ? 
                                    __x->__parent_unsafe()->__right_ : 
                                    __x->__parent_->__left_; 
                        // continue; 
                    } 
                    else  // __w has a red child 
                    { 
                        if (__w->__right_ == nullptr || __w->__right_->__is_black_) 
                        { 
                            // __w left child is non-null and red 
                            __w->__left_->__is_black_ = true; 
                            __w->__is_black_ = false; 
                            _VSTD::__tree_right_rotate(__w); 
                            // __w is known not to be root, so root hasn't changed 
                            // reset sibling, and it still can't be null 
                            __w = __w->__parent_unsafe(); 
                        } 
                        // __w has a right red child, left child may be null 
                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_; 
                        __w->__parent_unsafe()->__is_black_ = true; 
                        __w->__right_->__is_black_ = true; 
                        _VSTD::__tree_left_rotate(__w->__parent_unsafe()); 
                        break; 
                    } 
                } 
                else 
                { 
                    if (!__w->__is_black_) 
                    { 
                        __w->__is_black_ = true; 
                        __w->__parent_unsafe()->__is_black_ = false; 
                        _VSTD::__tree_right_rotate(__w->__parent_unsafe()); 
                        // __x is still valid 
                        // reset __root only if necessary 
                        if (__root == __w->__right_) 
                            __root = __w; 
                        // reset sibling, and it still can't be null 
                        __w = __w->__right_->__left_; 
                    } 
                    // __w->__is_black_ is now true, __w may have null children 
                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) && 
                        (__w->__right_ == nullptr || __w->__right_->__is_black_)) 
                    { 
                        __w->__is_black_ = false; 
                        __x = __w->__parent_unsafe(); 
                        // __x can no longer be null 
                        if (!__x->__is_black_ || __x == __root) 
                        { 
                            __x->__is_black_ = true; 
                            break; 
                        } 
                        // reset sibling, and it still can't be null 
                        __w = _VSTD::__tree_is_left_child(__x) ? 
                                    __x->__parent_unsafe()->__right_ : 
                                    __x->__parent_->__left_; 
                        // continue; 
                    } 
                    else  // __w has a red child 
                    { 
                        if (__w->__left_ == nullptr || __w->__left_->__is_black_) 
                        { 
                            // __w right child is non-null and red 
                            __w->__right_->__is_black_ = true; 
                            __w->__is_black_ = false; 
                            _VSTD::__tree_left_rotate(__w); 
                            // __w is known not to be root, so root hasn't changed 
                            // reset sibling, and it still can't be null 
                            __w = __w->__parent_unsafe(); 
                        } 
                        // __w has a left red child, right child may be null 
                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_; 
                        __w->__parent_unsafe()->__is_black_ = true; 
                        __w->__left_->__is_black_ = true; 
                        _VSTD::__tree_right_rotate(__w->__parent_unsafe()); 
                        break; 
                    } 
                } 
            } 
        } 
    } 
} 
 
// node traits 
 
 
template <class _Tp> 
struct __is_tree_value_type_imp : false_type {}; 
 
template <class _Key, class _Value> 
struct __is_tree_value_type_imp<__value_type<_Key, _Value> > : true_type {};
 
template <class ..._Args> 
struct __is_tree_value_type : false_type {}; 
 
template <class _One> 
struct __is_tree_value_type<_One> : __is_tree_value_type_imp<typename __uncvref<_One>::type> {}; 
 
template <class _Tp> 
struct __tree_key_value_types { 
  typedef _Tp key_type; 
  typedef _Tp __node_value_type; 
  typedef _Tp __container_value_type; 
  static const bool __is_map = false; 
 
  _LIBCPP_INLINE_VISIBILITY 
  static key_type const& __get_key(_Tp const& __v) { 
    return __v; 
  } 
  _LIBCPP_INLINE_VISIBILITY 
  static __container_value_type const& __get_value(__node_value_type const& __v) { 
    return __v; 
  } 
  _LIBCPP_INLINE_VISIBILITY 
  static __container_value_type* __get_ptr(__node_value_type& __n) { 
    return _VSTD::addressof(__n); 
  } 
  _LIBCPP_INLINE_VISIBILITY 
  static __container_value_type&& __move(__node_value_type& __v) {
    return _VSTD::move(__v); 
  } 
}; 
 
template <class _Key, class _Tp> 
struct __tree_key_value_types<__value_type<_Key, _Tp> > { 
  typedef _Key                                         key_type; 
  typedef _Tp                                          mapped_type; 
  typedef __value_type<_Key, _Tp>                      __node_value_type; 
  typedef pair<const _Key, _Tp>                        __container_value_type; 
  typedef __container_value_type                       __map_value_type; 
  static const bool __is_map = true; 
 
  _LIBCPP_INLINE_VISIBILITY 
  static key_type const& 
  __get_key(__node_value_type const& __t) { 
    return __t.__get_value().first; 
  } 
 
  template <class _Up> 
  _LIBCPP_INLINE_VISIBILITY 
  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value, 
      key_type const&>::type 
  __get_key(_Up& __t) { 
    return __t.first; 
  } 
 
  _LIBCPP_INLINE_VISIBILITY 
  static __container_value_type const& 
  __get_value(__node_value_type const& __t) { 
    return __t.__get_value(); 
  } 
 
  template <class _Up> 
  _LIBCPP_INLINE_VISIBILITY 
  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value, 
      __container_value_type const&>::type 
  __get_value(_Up& __t) { 
    return __t; 
  } 
 
  _LIBCPP_INLINE_VISIBILITY 
  static __container_value_type* __get_ptr(__node_value_type& __n) { 
    return _VSTD::addressof(__n.__get_value()); 
  } 
 
  _LIBCPP_INLINE_VISIBILITY 
  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) { 
    return __v.__move(); 
  } 
}; 
 
template <class _VoidPtr> 
struct __tree_node_base_types { 
  typedef _VoidPtr                                               __void_pointer; 
 
  typedef __tree_node_base<__void_pointer>                      __node_base_type; 
  typedef typename __rebind_pointer<_VoidPtr, __node_base_type>::type 
                                                             __node_base_pointer; 
 
  typedef __tree_end_node<__node_base_pointer>                  __end_node_type; 
  typedef typename __rebind_pointer<_VoidPtr, __end_node_type>::type 
                                                             __end_node_pointer; 
#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB) 
  typedef __end_node_pointer __parent_pointer; 
#else 
  typedef typename conditional< 
      is_pointer<__end_node_pointer>::value, 
        __end_node_pointer, 
        __node_base_pointer>::type __parent_pointer; 
#endif 
 
private: 
  static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value), 
                  "_VoidPtr does not point to unqualified void type"); 
}; 
 
template <class _Tp, class _AllocPtr, class _KVTypes = __tree_key_value_types<_Tp>, 
         bool = _KVTypes::__is_map> 
struct __tree_map_pointer_types {}; 
 
template <class _Tp, class _AllocPtr, class _KVTypes> 
struct __tree_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> { 
  typedef typename _KVTypes::__map_value_type   _Mv; 
  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type 
                                                       __map_value_type_pointer; 
  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type 
                                                 __const_map_value_type_pointer; 
}; 
 
template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type> 
struct __tree_node_types; 
 
template <class _NodePtr, class _Tp, class _VoidPtr> 
struct __tree_node_types<_NodePtr, __tree_node<_Tp, _VoidPtr> > 
    : public __tree_node_base_types<_VoidPtr>, 
             __tree_key_value_types<_Tp>, 
             __tree_map_pointer_types<_Tp, _VoidPtr> 
{ 
  typedef __tree_node_base_types<_VoidPtr> __base; 
  typedef __tree_key_value_types<_Tp>      __key_base; 
  typedef __tree_map_pointer_types<_Tp, _VoidPtr> __map_pointer_base; 
public: 
 
  typedef typename pointer_traits<_NodePtr>::element_type       __node_type; 
  typedef _NodePtr                                              __node_pointer; 
 
  typedef _Tp                                                 __node_value_type; 
  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type 
                                                      __node_value_type_pointer; 
  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type 
                                                __const_node_value_type_pointer; 
#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB) 
  typedef typename __base::__end_node_pointer __iter_pointer; 
#else 
  typedef typename conditional< 
      is_pointer<__node_pointer>::value, 
        typename __base::__end_node_pointer, 
        __node_pointer>::type __iter_pointer; 
#endif 
private: 
    static_assert(!is_const<__node_type>::value, 
                "_NodePtr should never be a pointer to const"); 
    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type, 
                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr."); 
}; 
 
template <class _ValueTp, class _VoidPtr> 
struct __make_tree_node_types { 
  typedef typename __rebind_pointer<_VoidPtr, __tree_node<_ValueTp, _VoidPtr> >::type 
                                                                        _NodePtr; 
  typedef __tree_node_types<_NodePtr> type; 
}; 
 
// node 
 
template <class _Pointer> 
class __tree_end_node 
{ 
public: 
    typedef _Pointer pointer; 
    pointer __left_; 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_end_node() _NOEXCEPT : __left_() {} 
}; 
 
template <class _VoidPtr> 
class _LIBCPP_STANDALONE_DEBUG __tree_node_base 
    : public __tree_node_base_types<_VoidPtr>::__end_node_type 
{ 
    typedef __tree_node_base_types<_VoidPtr> _NodeBaseTypes; 
 
public: 
    typedef typename _NodeBaseTypes::__node_base_pointer pointer; 
    typedef typename _NodeBaseTypes::__parent_pointer __parent_pointer; 
 
    pointer          __right_; 
    __parent_pointer __parent_; 
    bool __is_black_; 
 
    _LIBCPP_INLINE_VISIBILITY 
    pointer __parent_unsafe() const { return static_cast<pointer>(__parent_);} 
 
    _LIBCPP_INLINE_VISIBILITY 
    void __set_parent(pointer __p) { 
        __parent_ = static_cast<__parent_pointer>(__p); 
    } 
 
private: 
  ~__tree_node_base() = delete; 
  __tree_node_base(__tree_node_base const&) = delete; 
  __tree_node_base& operator=(__tree_node_base const&) = delete; 
}; 
 
template <class _Tp, class _VoidPtr> 
class _LIBCPP_STANDALONE_DEBUG __tree_node 
    : public __tree_node_base<_VoidPtr> 
{ 
public: 
    typedef _Tp __node_value_type; 
 
    __node_value_type __value_; 
 
private: 
  ~__tree_node() = delete; 
  __tree_node(__tree_node const&) = delete; 
  __tree_node& operator=(__tree_node const&) = delete; 
}; 
 
 
template <class _Allocator> 
class __tree_node_destructor 
{ 
    typedef _Allocator                                      allocator_type; 
    typedef allocator_traits<allocator_type>                __alloc_traits; 
 
public: 
    typedef typename __alloc_traits::pointer                pointer; 
private: 
    typedef __tree_node_types<pointer> _NodeTypes; 
    allocator_type& __na_; 
 
 
public: 
    bool __value_constructed; 
 
 
    __tree_node_destructor(const __tree_node_destructor &) = default; 
    __tree_node_destructor& operator=(const __tree_node_destructor&) = delete; 
 
    _LIBCPP_INLINE_VISIBILITY 
    explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT 
        : __na_(__na), 
          __value_constructed(__val) 
        {} 
 
    _LIBCPP_INLINE_VISIBILITY 
    void operator()(pointer __p) _NOEXCEPT 
    { 
        if (__value_constructed) 
            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_)); 
        if (__p) 
            __alloc_traits::deallocate(__na_, __p, 1); 
    } 
 
    template <class> friend class __map_node_destructor; 
}; 
 
#if _LIBCPP_STD_VER > 14
template <class _NodeType, class _Alloc>
struct __generic_container_node_destructor;
template <class _Tp, class _VoidPtr, class _Alloc>
struct __generic_container_node_destructor<__tree_node<_Tp, _VoidPtr>, _Alloc>
    : __tree_node_destructor<_Alloc>
{
    using __tree_node_destructor<_Alloc>::__tree_node_destructor;
};
#endif
 
template <class _Tp, class _NodePtr, class _DiffType> 
class _LIBCPP_TEMPLATE_VIS __tree_iterator 
{ 
    typedef __tree_node_types<_NodePtr>                     _NodeTypes; 
    typedef _NodePtr                                        __node_pointer; 
    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer; 
    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer; 
    typedef typename _NodeTypes::__iter_pointer             __iter_pointer; 
    typedef pointer_traits<__node_pointer> __pointer_traits; 
 
    __iter_pointer __ptr_; 
 
public: 
    typedef bidirectional_iterator_tag                     iterator_category; 
    typedef _Tp                                            value_type; 
    typedef _DiffType                                      difference_type; 
    typedef value_type&                                    reference; 
    typedef typename _NodeTypes::__node_value_type_pointer pointer; 
 
    _LIBCPP_INLINE_VISIBILITY __tree_iterator() _NOEXCEPT 
#if _LIBCPP_STD_VER > 11 
    : __ptr_(nullptr) 
#endif 
    {} 
 
    _LIBCPP_INLINE_VISIBILITY reference operator*() const 
        {return __get_np()->__value_;} 
    _LIBCPP_INLINE_VISIBILITY pointer operator->() const 
        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);} 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_iterator& operator++() { 
      __ptr_ = static_cast<__iter_pointer>( 
          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_))); 
      return *this; 
    } 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_iterator operator++(int) 
        {__tree_iterator __t(*this); ++(*this); return __t;} 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_iterator& operator--() { 
      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>( 
          static_cast<__end_node_pointer>(__ptr_))); 
      return *this; 
    } 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_iterator operator--(int) 
        {__tree_iterator __t(*this); --(*this); return __t;} 
 
    friend _LIBCPP_INLINE_VISIBILITY 
        bool operator==(const __tree_iterator& __x, const __tree_iterator& __y) 
        {return __x.__ptr_ == __y.__ptr_;} 
    friend _LIBCPP_INLINE_VISIBILITY 
        bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y) 
        {return !(__x == __y);} 
 
private: 
    _LIBCPP_INLINE_VISIBILITY 
    explicit __tree_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {} 
    _LIBCPP_INLINE_VISIBILITY 
    explicit __tree_iterator(__end_node_pointer __p) _NOEXCEPT : __ptr_(__p) {} 
    _LIBCPP_INLINE_VISIBILITY 
    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); } 
    template <class, class, class> friend class __tree; 
    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS __tree_const_iterator; 
    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_iterator; 
    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map; 
    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap; 
    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set; 
    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset; 
}; 
 
template <class _Tp, class _NodePtr, class _DiffType> 
class _LIBCPP_TEMPLATE_VIS __tree_const_iterator 
{ 
    typedef __tree_node_types<_NodePtr>                     _NodeTypes; 
    typedef typename _NodeTypes::__node_pointer             __node_pointer; 
    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer; 
    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer; 
    typedef typename _NodeTypes::__iter_pointer             __iter_pointer; 
    typedef pointer_traits<__node_pointer> __pointer_traits; 
 
    __iter_pointer __ptr_; 
 
public: 
    typedef bidirectional_iterator_tag                           iterator_category; 
    typedef _Tp                                                  value_type; 
    typedef _DiffType                                            difference_type; 
    typedef const value_type&                                    reference; 
    typedef typename _NodeTypes::__const_node_value_type_pointer pointer; 
 
    _LIBCPP_INLINE_VISIBILITY __tree_const_iterator() _NOEXCEPT 
#if _LIBCPP_STD_VER > 11 
    : __ptr_(nullptr) 
#endif 
    {} 
 
private: 
    typedef __tree_iterator<value_type, __node_pointer, difference_type> 
                                                           __non_const_iterator; 
public: 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT 
        : __ptr_(__p.__ptr_) {} 
 
    _LIBCPP_INLINE_VISIBILITY reference operator*() const 
        {return __get_np()->__value_;} 
    _LIBCPP_INLINE_VISIBILITY pointer operator->() const 
        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);} 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_const_iterator& operator++() { 
      __ptr_ = static_cast<__iter_pointer>( 
          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_))); 
      return *this; 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_const_iterator operator++(int) 
        {__tree_const_iterator __t(*this); ++(*this); return __t;} 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_const_iterator& operator--() { 
      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>( 
          static_cast<__end_node_pointer>(__ptr_))); 
      return *this; 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    __tree_const_iterator operator--(int) 
        {__tree_const_iterator __t(*this); --(*this); return __t;} 
 
    friend _LIBCPP_INLINE_VISIBILITY 
        bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y) 
        {return __x.__ptr_ == __y.__ptr_;} 
    friend _LIBCPP_INLINE_VISIBILITY 
        bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y) 
        {return !(__x == __y);} 
 
private: 
    _LIBCPP_INLINE_VISIBILITY 
    explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT 
        : __ptr_(__p) {} 
    _LIBCPP_INLINE_VISIBILITY 
    explicit __tree_const_iterator(__end_node_pointer __p) _NOEXCEPT 
        : __ptr_(__p) {} 
    _LIBCPP_INLINE_VISIBILITY 
    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); } 
 
    template <class, class, class> friend class __tree; 
    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map; 
    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap; 
    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set; 
    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset; 
    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_const_iterator; 
 
}; 
 
template<class _Tp, class _Compare>
#ifndef _LIBCPP_CXX03_LANG 
    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Compare const&, _Tp const&, _Tp const&>::value, 
        "the specified comparator type does not provide a viable const call operator") 
#endif
int __diagnose_non_const_comparator();
 
template <class _Tp, class _Compare, class _Allocator> 
class __tree 
{ 
public: 
    typedef _Tp                                      value_type; 
    typedef _Compare                                 value_compare; 
    typedef _Allocator                               allocator_type; 
 
private: 
    typedef allocator_traits<allocator_type>         __alloc_traits; 
    typedef typename __make_tree_node_types<value_type, 
        typename __alloc_traits::void_pointer>::type 
                                                    _NodeTypes; 
    typedef typename _NodeTypes::key_type           key_type; 
public: 
    typedef typename _NodeTypes::__node_value_type      __node_value_type; 
    typedef typename _NodeTypes::__container_value_type __container_value_type; 
 
    typedef typename __alloc_traits::pointer         pointer; 
    typedef typename __alloc_traits::const_pointer   const_pointer; 
    typedef typename __alloc_traits::size_type       size_type; 
    typedef typename __alloc_traits::difference_type difference_type; 
 
public: 
    typedef typename _NodeTypes::__void_pointer        __void_pointer; 
 
    typedef typename _NodeTypes::__node_type           __node; 
    typedef typename _NodeTypes::__node_pointer        __node_pointer; 
 
    typedef typename _NodeTypes::__node_base_type      __node_base; 
    typedef typename _NodeTypes::__node_base_pointer   __node_base_pointer; 
 
    typedef typename _NodeTypes::__end_node_type       __end_node_t; 
    typedef typename _NodeTypes::__end_node_pointer    __end_node_ptr; 
 
    typedef typename _NodeTypes::__parent_pointer      __parent_pointer; 
    typedef typename _NodeTypes::__iter_pointer        __iter_pointer; 
 
    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator; 
    typedef allocator_traits<__node_allocator>         __node_traits; 
 
private: 
    // check for sane allocator pointer rebinding semantics. Rebinding the 
    // allocator for a new pointer type should be exactly the same as rebinding 
    // the pointer using 'pointer_traits'. 
    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value), 
                  "Allocator does not rebind pointers in a sane manner."); 
    typedef typename __rebind_alloc_helper<__node_traits, __node_base>::type 
        __node_base_allocator; 
    typedef allocator_traits<__node_base_allocator> __node_base_traits; 
    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value), 
                 "Allocator does not rebind pointers in a sane manner."); 
 
private: 
    __iter_pointer                                     __begin_node_; 
    __compressed_pair<__end_node_t, __node_allocator>  __pair1_; 
    __compressed_pair<size_type, value_compare>        __pair3_; 
 
public: 
    _LIBCPP_INLINE_VISIBILITY 
    __iter_pointer __end_node() _NOEXCEPT 
    { 
        return static_cast<__iter_pointer>( 
                pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first()) 
        ); 
    } 
    _LIBCPP_INLINE_VISIBILITY 
    __iter_pointer __end_node() const _NOEXCEPT 
    { 
        return static_cast<__iter_pointer>( 
            pointer_traits<__end_node_ptr>::pointer_to( 
                const_cast<__end_node_t&>(__pair1_.first()) 
            ) 
        ); 
    } 
    _LIBCPP_INLINE_VISIBILITY 
          __node_allocator& __node_alloc() _NOEXCEPT {return __pair1_.second();} 
private: 
    _LIBCPP_INLINE_VISIBILITY 
    const __node_allocator& __node_alloc() const _NOEXCEPT 
        {return __pair1_.second();} 
    _LIBCPP_INLINE_VISIBILITY 
          __iter_pointer& __begin_node() _NOEXCEPT {return __begin_node_;} 
    _LIBCPP_INLINE_VISIBILITY 
    const __iter_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;} 
public: 
    _LIBCPP_INLINE_VISIBILITY 
    allocator_type __alloc() const _NOEXCEPT 
        {return allocator_type(__node_alloc());} 
private: 
    _LIBCPP_INLINE_VISIBILITY 
          size_type& size() _NOEXCEPT {return __pair3_.first();} 
public: 
    _LIBCPP_INLINE_VISIBILITY 
    const size_type& size() const _NOEXCEPT {return __pair3_.first();} 
    _LIBCPP_INLINE_VISIBILITY 
          value_compare& value_comp() _NOEXCEPT {return __pair3_.second();} 
    _LIBCPP_INLINE_VISIBILITY 
    const value_compare& value_comp() const _NOEXCEPT 
        {return __pair3_.second();} 
public: 
 
    _LIBCPP_INLINE_VISIBILITY 
    __node_pointer __root() const _NOEXCEPT 
        {return static_cast<__node_pointer>(__end_node()->__left_);} 
 
    __node_base_pointer* __root_ptr() const _NOEXCEPT { 
        return _VSTD::addressof(__end_node()->__left_); 
    } 
 
    typedef __tree_iterator<value_type, __node_pointer, difference_type>             iterator; 
    typedef __tree_const_iterator<value_type, __node_pointer, difference_type> const_iterator; 
 
    explicit __tree(const value_compare& __comp) 
        _NOEXCEPT_( 
            is_nothrow_default_constructible<__node_allocator>::value && 
            is_nothrow_copy_constructible<value_compare>::value); 
    explicit __tree(const allocator_type& __a); 
    __tree(const value_compare& __comp, const allocator_type& __a); 
    __tree(const __tree& __t); 
    __tree& operator=(const __tree& __t); 
    template <class _ForwardIterator> 
        void __assign_unique(_ForwardIterator __first, _ForwardIterator __last); 
    template <class _InputIterator> 
        void __assign_multi(_InputIterator __first, _InputIterator __last); 
    __tree(__tree&& __t) 
        _NOEXCEPT_( 
            is_nothrow_move_constructible<__node_allocator>::value && 
            is_nothrow_move_constructible<value_compare>::value); 
    __tree(__tree&& __t, const allocator_type& __a); 
    __tree& operator=(__tree&& __t) 
        _NOEXCEPT_( 
            __node_traits::propagate_on_container_move_assignment::value && 
            is_nothrow_move_assignable<value_compare>::value && 
            is_nothrow_move_assignable<__node_allocator>::value); 
    ~__tree(); 
 
    _LIBCPP_INLINE_VISIBILITY 
          iterator begin()  _NOEXCEPT {return       iterator(__begin_node());} 
    _LIBCPP_INLINE_VISIBILITY 
    const_iterator begin() const _NOEXCEPT {return const_iterator(__begin_node());} 
    _LIBCPP_INLINE_VISIBILITY 
          iterator end() _NOEXCEPT {return       iterator(__end_node());} 
    _LIBCPP_INLINE_VISIBILITY 
    const_iterator end() const _NOEXCEPT {return const_iterator(__end_node());} 
 
    _LIBCPP_INLINE_VISIBILITY 
    size_type max_size() const _NOEXCEPT 
        {return _VSTD::min<size_type>( 
                __node_traits::max_size(__node_alloc()),
                numeric_limits<difference_type >::max());}
 
    void clear() _NOEXCEPT; 
 
    void swap(__tree& __t) 
#if _LIBCPP_STD_VER <= 11 
        _NOEXCEPT_( 
            __is_nothrow_swappable<value_compare>::value 
            && (!__node_traits::propagate_on_container_swap::value || 
                 __is_nothrow_swappable<__node_allocator>::value) 
            ); 
#else 
        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value); 
#endif 
 
    template <class _Key, class ..._Args> 
    pair<iterator, bool> 
    __emplace_unique_key_args(_Key const&, _Args&&... __args); 
    template <class _Key, class ..._Args> 
    pair<iterator, bool> 
    __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&&...); 
 
    template <class... _Args> 
    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args); 
 
    template <class... _Args> 
    iterator __emplace_hint_unique_impl(const_iterator __p, _Args&&... __args); 
 
    template <class... _Args> 
    iterator __emplace_multi(_Args&&... __args); 
 
    template <class... _Args> 
    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args); 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> __emplace_unique(_Pp&& __x) { 
        return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x), 
                                            __can_extract_key<_Pp, key_type>()); 
    } 
 
    template <class _First, class _Second> 
    _LIBCPP_INLINE_VISIBILITY 
    typename enable_if< 
        __can_extract_map_key<_First, key_type, __container_value_type>::value, 
        pair<iterator, bool> 
    >::type __emplace_unique(_First&& __f, _Second&& __s) { 
        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f), 
                                              _VSTD::forward<_Second>(__s)); 
    } 
 
    template <class... _Args> 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> __emplace_unique(_Args&&... __args) { 
        return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...); 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> 
    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) { 
      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x)); 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> 
    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) { 
      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x)); 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> 
    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) { 
      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x)); 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __emplace_hint_unique(const_iterator __p, _Pp&& __x) { 
        return __emplace_hint_unique_extract_key(__p, _VSTD::forward<_Pp>(__x), 
                                            __can_extract_key<_Pp, key_type>()); 
    } 
 
    template <class _First, class _Second> 
    _LIBCPP_INLINE_VISIBILITY 
    typename enable_if< 
        __can_extract_map_key<_First, key_type, __container_value_type>::value, 
        iterator 
    >::type __emplace_hint_unique(const_iterator __p, _First&& __f, _Second&& __s) { 
        return __emplace_hint_unique_key_args(__p, __f, 
                                              _VSTD::forward<_First>(__f), 
                                              _VSTD::forward<_Second>(__s)).first; 
    } 
 
    template <class... _Args> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __emplace_hint_unique(const_iterator __p, _Args&&... __args) { 
        return __emplace_hint_unique_impl(__p, _VSTD::forward<_Args>(__args)...); 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator 
    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_fail_tag) { 
      return __emplace_hint_unique_impl(__p, _VSTD::forward<_Pp>(__x)); 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator 
    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_self_tag) { 
      return __emplace_hint_unique_key_args(__p, __x, _VSTD::forward<_Pp>(__x)).first; 
    } 
 
    template <class _Pp> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator 
    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_first_tag) { 
      return __emplace_hint_unique_key_args(__p, __x.first, _VSTD::forward<_Pp>(__x)).first; 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> __insert_unique(const __container_value_type& __v) { 
        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), __v); 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_unique(const_iterator __p, const __container_value_type& __v) { 
        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), __v).first; 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> __insert_unique(__container_value_type&& __v) { 
        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), _VSTD::move(__v)); 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_unique(const_iterator __p, __container_value_type&& __v) { 
        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), _VSTD::move(__v)).first; 
    } 
 
    template <class _Vp, class = typename enable_if< 
            !is_same<typename __unconstref<_Vp>::type, 
                     __container_value_type 
            >::value 
        >::type> 
    _LIBCPP_INLINE_VISIBILITY 
    pair<iterator, bool> __insert_unique(_Vp&& __v) { 
        return __emplace_unique(_VSTD::forward<_Vp>(__v)); 
    } 
 
    template <class _Vp, class = typename enable_if< 
            !is_same<typename __unconstref<_Vp>::type, 
                     __container_value_type 
            >::value 
        >::type> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_unique(const_iterator __p, _Vp&& __v) { 
        return __emplace_hint_unique(__p, _VSTD::forward<_Vp>(__v)); 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_multi(__container_value_type&& __v) { 
        return __emplace_multi(_VSTD::move(__v)); 
    } 
 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_multi(const_iterator __p, __container_value_type&& __v) { 
        return __emplace_hint_multi(__p, _VSTD::move(__v)); 
    } 
 
    template <class _Vp> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_multi(_Vp&& __v) { 
        return __emplace_multi(_VSTD::forward<_Vp>(__v)); 
    } 
 
    template <class _Vp> 
    _LIBCPP_INLINE_VISIBILITY 
    iterator __insert_multi(const_iterator __p, _Vp&& __v) { 
        return __emplace_hint_multi(__p, _VSTD::forward<_Vp>(__v)); 
    } 
 
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __node_assign_unique(const __container_value_type& __v, __node_pointer __dest); 
 
    _LIBCPP_INLINE_VISIBILITY
    iterator __node_insert_multi(__node_pointer __nd); 
    _LIBCPP_INLINE_VISIBILITY
    iterator __node_insert_multi(const_iterator __p, __node_pointer __nd); 
 

    _LIBCPP_INLINE_VISIBILITY iterator
    __remove_node_pointer(__node_pointer) _NOEXCEPT;

#if _LIBCPP_STD_VER > 14
    template <class _NodeHandle, class _InsertReturnType>
    _LIBCPP_INLINE_VISIBILITY
    _InsertReturnType __node_handle_insert_unique(_NodeHandle&&);
    template <class _NodeHandle>
    _LIBCPP_INLINE_VISIBILITY
    iterator __node_handle_insert_unique(const_iterator, _NodeHandle&&);
    template <class _Tree>
    _LIBCPP_INLINE_VISIBILITY
    void __node_handle_merge_unique(_Tree& __source);

    template <class _NodeHandle>
    _LIBCPP_INLINE_VISIBILITY
    iterator __node_handle_insert_multi(_NodeHandle&&);
    template <class _NodeHandle>
    _LIBCPP_INLINE_VISIBILITY
    iterator __node_handle_insert_multi(const_iterator, _NodeHandle&&);
    template <class _Tree>
    _LIBCPP_INLINE_VISIBILITY
    void __node_handle_merge_multi(_Tree& __source);


    template <class _NodeHandle>
    _LIBCPP_INLINE_VISIBILITY
    _NodeHandle __node_handle_extract(key_type const&);
    template <class _NodeHandle>
    _LIBCPP_INLINE_VISIBILITY
    _NodeHandle __node_handle_extract(const_iterator);
#endif

    iterator erase(const_iterator __p); 
    iterator erase(const_iterator __f, const_iterator __l); 
    template <class _Key> 
        size_type __erase_unique(const _Key& __k); 
    template <class _Key> 
        size_type __erase_multi(const _Key& __k); 
 
    void __insert_node_at(__parent_pointer     __parent, 
                          __node_base_pointer& __child, 
                          __node_base_pointer __new_node) _NOEXCEPT;
 
    template <class _Key> 
        iterator find(const _Key& __v); 
    template <class _Key> 
        const_iterator find(const _Key& __v) const; 
 
    template <class _Key> 
        size_type __count_unique(const _Key& __k) const; 
    template <class _Key> 
        size_type __count_multi(const _Key& __k) const; 
 
    template <class _Key> 
        _LIBCPP_INLINE_VISIBILITY 
        iterator lower_bound(const _Key& __v) 
            {return __lower_bound(__v, __root(), __end_node());} 
    template <class _Key> 
        iterator __lower_bound(const _Key& __v, 
                               __node_pointer __root, 
                               __iter_pointer __result); 
    template <class _Key> 
        _LIBCPP_INLINE_VISIBILITY 
        const_iterator lower_bound(const _Key& __v) const 
            {return __lower_bound(__v, __root(), __end_node());} 
    template <class _Key> 
        const_iterator __lower_bound(const _Key& __v, 
                                     __node_pointer __root, 
                                     __iter_pointer __result) const; 
    template <class _Key> 
        _LIBCPP_INLINE_VISIBILITY 
        iterator upper_bound(const _Key& __v) 
            {return __upper_bound(__v, __root(), __end_node());} 
    template <class _Key> 
        iterator __upper_bound(const _Key& __v, 
                               __node_pointer __root, 
                               __iter_pointer __result); 
    template <class _Key> 
        _LIBCPP_INLINE_VISIBILITY 
        const_iterator upper_bound(const _Key& __v) const 
            {return __upper_bound(__v, __root(), __end_node());} 
    template <class _Key> 
        const_iterator __upper_bound(const _Key& __v, 
                                     __node_pointer __root, 
                                     __iter_pointer __result) const; 
    template <class _Key> 
        pair<iterator, iterator> 
        __equal_range_unique(const _Key& __k); 
    template <class _Key> 
        pair<const_iterator, const_iterator> 
        __equal_range_unique(const _Key& __k) const; 
 
    template <class _Key> 
        pair<iterator, iterator> 
        __equal_range_multi(const _Key& __k); 
    template <class _Key> 
        pair<const_iterator, const_iterator> 
        __equal_range_multi(const _Key& __k) const; 
 
    typedef __tree_node_destructor<__node_allocator> _Dp; 
    typedef unique_ptr<__node, _Dp> __node_holder; 
 
    __node_holder remove(const_iterator __p) _NOEXCEPT; 
private: 
    __node_base_pointer& 
        __find_leaf_low(__parent_pointer& __parent, const key_type& __v); 
    __node_base_pointer& 
        __find_leaf_high(__parent_pointer& __parent, const key_type& __v); 
    __node_base_pointer& 
        __find_leaf(const_iterator __hint, 
                    __parent_pointer& __parent, const key_type& __v); 
    // FIXME: Make this function const qualified. Unfortunately doing so 
    // breaks existing code which uses non-const callable comparators. 
    template <class _Key> 
    __node_base_pointer& 
        __find_equal(__parent_pointer& __parent, const _Key& __v); 
    template <class _Key> 
    _LIBCPP_INLINE_VISIBILITY __node_base_pointer& 
    __find_equal(__parent_pointer& __parent, const _Key& __v) const { 
      return const_cast<__tree*>(this)->__find_equal(__parent, __v); 
    } 
    template <class _Key> 
    __node_base_pointer& 
        __find_equal(const_iterator __hint, __parent_pointer& __parent, 
                     __node_base_pointer& __dummy, 
                     const _Key& __v); 
 
    template <class ..._Args> 
    __node_holder __construct_node(_Args&& ...__args); 
 
    void destroy(__node_pointer __nd) _NOEXCEPT; 
 
    _LIBCPP_INLINE_VISIBILITY 
    void __copy_assign_alloc(const __tree& __t) 
        {__copy_assign_alloc(__t, integral_constant<bool, 
             __node_traits::propagate_on_container_copy_assignment::value>());} 
 
    _LIBCPP_INLINE_VISIBILITY 
    void __copy_assign_alloc(const __tree& __t, true_type) 
        { 
        if (__node_alloc() != __t.__node_alloc()) 
            clear();
        __node_alloc() = __t.__node_alloc(); 
        } 
    _LIBCPP_INLINE_VISIBILITY 
    void __copy_assign_alloc(const __tree&, false_type) {} 
 
    void __move_assign(__tree& __t, false_type); 
    void __move_assign(__tree& __t, true_type) 
        _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value && 
                   is_nothrow_move_assignable<__node_allocator>::value); 
 
    _LIBCPP_INLINE_VISIBILITY 
    void __move_assign_alloc(__tree& __t) 
        _NOEXCEPT_( 
            !__node_traits::propagate_on_container_move_assignment::value || 
            is_nothrow_move_assignable<__node_allocator>::value) 
        {__move_assign_alloc(__t, integral_constant<bool, 
             __node_traits::propagate_on_container_move_assignment::value>());} 
 
    _LIBCPP_INLINE_VISIBILITY 
    void __move_assign_alloc(__tree& __t, true_type) 
        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value) 
        {__node_alloc() = _VSTD::move(__t.__node_alloc());} 
    _LIBCPP_INLINE_VISIBILITY 
    void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {} 
 
    struct _DetachedTreeCache { 
      _LIBCPP_INLINE_VISIBILITY 
      explicit _DetachedTreeCache(__tree *__t) _NOEXCEPT : __t_(__t), 
        __cache_root_(__detach_from_tree(__t)) { 
          __advance(); 
        } 
 
      _LIBCPP_INLINE_VISIBILITY 
      __node_pointer __get() const _NOEXCEPT { 
        return __cache_elem_; 
      } 
 
      _LIBCPP_INLINE_VISIBILITY 
      void __advance() _NOEXCEPT { 
        __cache_elem_ = __cache_root_; 
        if (__cache_root_) { 
          __cache_root_ = __detach_next(__cache_root_); 
        } 
      } 
 
      _LIBCPP_INLINE_VISIBILITY 
      ~_DetachedTreeCache() { 
        __t_->destroy(__cache_elem_); 
        if (__cache_root_) { 
          while (__cache_root_->__parent_ != nullptr) 
            __cache_root_ = static_cast<__node_pointer>(__cache_root_->__parent_); 
          __t_->destroy(__cache_root_); 
        } 
      } 
 
       _DetachedTreeCache(_DetachedTreeCache const&) = delete; 
       _DetachedTreeCache& operator=(_DetachedTreeCache const&) = delete; 
 
    private: 
      _LIBCPP_INLINE_VISIBILITY 
      static __node_pointer __detach_from_tree(__tree *__t) _NOEXCEPT; 
      _LIBCPP_INLINE_VISIBILITY 
      static __node_pointer __detach_next(__node_pointer) _NOEXCEPT; 
 
      __tree *__t_; 
      __node_pointer __cache_root_; 
      __node_pointer __cache_elem_; 
    }; 
 
 
    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map; 
    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap; 
}; 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp) 
        _NOEXCEPT_( 
            is_nothrow_default_constructible<__node_allocator>::value && 
            is_nothrow_copy_constructible<value_compare>::value) 
    : __pair3_(0, __comp) 
{ 
    __begin_node() = __end_node(); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a) 
    : __begin_node_(__iter_pointer()), 
      __pair1_(__default_init_tag(), __node_allocator(__a)), 
      __pair3_(0, __default_init_tag()) 
{ 
    __begin_node() = __end_node(); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp, 
                                           const allocator_type& __a) 
    : __begin_node_(__iter_pointer()), 
      __pair1_(__default_init_tag(), __node_allocator(__a)), 
      __pair3_(0, __comp) 
{ 
    __begin_node() = __end_node(); 
} 
 
// Precondition:  size() != 0 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::__node_pointer 
__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_from_tree(__tree *__t) _NOEXCEPT 
{ 
    __node_pointer __cache = static_cast<__node_pointer>(__t->__begin_node()); 
    __t->__begin_node() = __t->__end_node(); 
    __t->__end_node()->__left_->__parent_ = nullptr; 
    __t->__end_node()->__left_ = nullptr; 
    __t->size() = 0; 
    // __cache->__left_ == nullptr 
    if (__cache->__right_ != nullptr) 
        __cache = static_cast<__node_pointer>(__cache->__right_); 
    // __cache->__left_ == nullptr 
    // __cache->__right_ == nullptr 
    return __cache; 
} 
 
// Precondition:  __cache != nullptr 
//    __cache->left_ == nullptr 
//    __cache->right_ == nullptr 
//    This is no longer a red-black tree 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::__node_pointer 
__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_next(__node_pointer __cache) _NOEXCEPT 
{ 
    if (__cache->__parent_ == nullptr) 
        return nullptr; 
    if (_VSTD::__tree_is_left_child(static_cast<__node_base_pointer>(__cache))) 
    { 
        __cache->__parent_->__left_ = nullptr; 
        __cache = static_cast<__node_pointer>(__cache->__parent_); 
        if (__cache->__right_ == nullptr) 
            return __cache; 
        return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__right_)); 
    } 
    // __cache is right child 
    __cache->__parent_unsafe()->__right_ = nullptr; 
    __cache = static_cast<__node_pointer>(__cache->__parent_); 
    if (__cache->__left_ == nullptr) 
        return __cache; 
    return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__left_)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>& 
__tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t) 
{ 
    if (this != _VSTD::addressof(__t)) 
    { 
        value_comp() = __t.value_comp(); 
        __copy_assign_alloc(__t); 
        __assign_multi(__t.begin(), __t.end()); 
    } 
    return *this; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _ForwardIterator> 
void 
__tree<_Tp, _Compare, _Allocator>::__assign_unique(_ForwardIterator __first, _ForwardIterator __last) 
{ 
    typedef iterator_traits<_ForwardIterator> _ITraits; 
    typedef typename _ITraits::value_type _ItValueType; 
    static_assert((is_same<_ItValueType, __container_value_type>::value), 
                  "__assign_unique may only be called with the containers value type"); 
    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value, 
                  "__assign_unique requires a forward iterator"); 
    if (size() != 0) 
    { 
        _DetachedTreeCache __cache(this); 
          for (; __cache.__get() != nullptr && __first != __last; ++__first) { 
              if (__node_assign_unique(*__first, __cache.__get()).second) 
                  __cache.__advance(); 
            }
    } 
    for (; __first != __last; ++__first) 
        __insert_unique(*__first); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _InputIterator> 
void 
__tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _InputIterator __last) 
{ 
    typedef iterator_traits<_InputIterator> _ITraits; 
    typedef typename _ITraits::value_type _ItValueType; 
    static_assert((is_same<_ItValueType, __container_value_type>::value || 
                  is_same<_ItValueType, __node_value_type>::value), 
                  "__assign_multi may only be called with the containers value type" 
                  " or the nodes value type"); 
    if (size() != 0) 
    { 
        _DetachedTreeCache __cache(this); 
        for (; __cache.__get() && __first != __last; ++__first) { 
            __cache.__get()->__value_ = *__first; 
            __node_insert_multi(__cache.__get()); 
            __cache.__advance(); 
        } 
    } 
    for (; __first != __last; ++__first) 
        __insert_multi(_NodeTypes::__get_value(*__first)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t) 
    : __begin_node_(__iter_pointer()), 
      __pair1_(__default_init_tag(), __node_traits::select_on_container_copy_construction(__t.__node_alloc())), 
      __pair3_(0, __t.value_comp()) 
{ 
    __begin_node() = __end_node(); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t) 
    _NOEXCEPT_( 
        is_nothrow_move_constructible<__node_allocator>::value && 
        is_nothrow_move_constructible<value_compare>::value) 
    : __begin_node_(_VSTD::move(__t.__begin_node_)), 
      __pair1_(_VSTD::move(__t.__pair1_)), 
      __pair3_(_VSTD::move(__t.__pair3_)) 
{ 
    if (size() == 0) 
        __begin_node() = __end_node(); 
    else 
    { 
        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
        __t.__begin_node() = __t.__end_node(); 
        __t.__end_node()->__left_ = nullptr; 
        __t.size() = 0; 
    } 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a) 
    : __pair1_(__default_init_tag(), __node_allocator(__a)), 
      __pair3_(0, _VSTD::move(__t.value_comp())) 
{ 
    if (__a == __t.__alloc()) 
    { 
        if (__t.size() == 0) 
            __begin_node() = __end_node(); 
        else 
        { 
            __begin_node() = __t.__begin_node(); 
            __end_node()->__left_ = __t.__end_node()->__left_; 
            __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
            size() = __t.size(); 
            __t.__begin_node() = __t.__end_node(); 
            __t.__end_node()->__left_ = nullptr; 
            __t.size() = 0; 
        } 
    } 
    else 
    { 
        __begin_node() = __end_node(); 
    } 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
void 
__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type) 
    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value && 
               is_nothrow_move_assignable<__node_allocator>::value) 
{ 
    destroy(static_cast<__node_pointer>(__end_node()->__left_)); 
    __begin_node_ = __t.__begin_node_; 
    __pair1_.first() = __t.__pair1_.first(); 
    __move_assign_alloc(__t); 
    __pair3_ = _VSTD::move(__t.__pair3_); 
    if (size() == 0) 
        __begin_node() = __end_node(); 
    else 
    { 
        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
        __t.__begin_node() = __t.__end_node(); 
        __t.__end_node()->__left_ = nullptr; 
        __t.size() = 0; 
    } 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
void 
__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type) 
{ 
    if (__node_alloc() == __t.__node_alloc()) 
        __move_assign(__t, true_type()); 
    else 
    { 
        value_comp() = _VSTD::move(__t.value_comp()); 
        const_iterator __e = end(); 
        if (size() != 0) 
        { 
            _DetachedTreeCache __cache(this); 
            while (__cache.__get() != nullptr && __t.size() != 0) { 
              __cache.__get()->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_); 
              __node_insert_multi(__cache.__get()); 
              __cache.__advance(); 
            } 
        } 
        while (__t.size() != 0) 
            __insert_multi(__e, _NodeTypes::__move(__t.remove(__t.begin())->__value_)); 
    } 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>& 
__tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t) 
    _NOEXCEPT_( 
        __node_traits::propagate_on_container_move_assignment::value && 
        is_nothrow_move_assignable<value_compare>::value && 
        is_nothrow_move_assignable<__node_allocator>::value) 
 
{ 
    __move_assign(__t, integral_constant<bool, 
                  __node_traits::propagate_on_container_move_assignment::value>()); 
    return *this; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
__tree<_Tp, _Compare, _Allocator>::~__tree() 
{ 
    static_assert((is_copy_constructible<value_compare>::value), 
                 "Comparator must be copy-constructible."); 
  destroy(__root()); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
void 
__tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT 
{ 
    if (__nd != nullptr) 
    { 
        destroy(static_cast<__node_pointer>(__nd->__left_)); 
        destroy(static_cast<__node_pointer>(__nd->__right_)); 
        __node_allocator& __na = __node_alloc(); 
        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__nd->__value_)); 
        __node_traits::deallocate(__na, __nd, 1); 
    } 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
void 
__tree<_Tp, _Compare, _Allocator>::swap(__tree& __t) 
#if _LIBCPP_STD_VER <= 11 
        _NOEXCEPT_( 
            __is_nothrow_swappable<value_compare>::value 
            && (!__node_traits::propagate_on_container_swap::value || 
                 __is_nothrow_swappable<__node_allocator>::value) 
            ) 
#else 
        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value) 
#endif 
{ 
    using _VSTD::swap; 
    swap(__begin_node_, __t.__begin_node_); 
    swap(__pair1_.first(), __t.__pair1_.first()); 
    _VSTD::__swap_allocator(__node_alloc(), __t.__node_alloc()); 
    __pair3_.swap(__t.__pair3_); 
    if (size() == 0) 
        __begin_node() = __end_node(); 
    else 
        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
    if (__t.size() == 0) 
        __t.__begin_node() = __t.__end_node(); 
    else 
        __t.__end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__t.__end_node()); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
void 
__tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT 
{ 
    destroy(__root()); 
    size() = 0; 
    __begin_node() = __end_node(); 
    __end_node()->__left_ = nullptr; 
} 
 
// Find lower_bound place to insert 
// Set __parent to parent of null leaf 
// Return reference to null leaf 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(__parent_pointer& __parent, 
                                                   const key_type& __v) 
{ 
    __node_pointer __nd = __root(); 
    if (__nd != nullptr) 
    { 
        while (true) 
        { 
            if (value_comp()(__nd->__value_, __v)) 
            { 
                if (__nd->__right_ != nullptr) 
                    __nd = static_cast<__node_pointer>(__nd->__right_); 
                else 
                { 
                    __parent = static_cast<__parent_pointer>(__nd); 
                    return __nd->__right_; 
                } 
            } 
            else 
            { 
                if (__nd->__left_ != nullptr) 
                    __nd = static_cast<__node_pointer>(__nd->__left_); 
                else 
                { 
                    __parent = static_cast<__parent_pointer>(__nd); 
                    return __parent->__left_; 
                } 
            } 
        } 
    } 
    __parent = static_cast<__parent_pointer>(__end_node()); 
    return __parent->__left_; 
} 
 
// Find upper_bound place to insert 
// Set __parent to parent of null leaf 
// Return reference to null leaf 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(__parent_pointer& __parent, 
                                                    const key_type& __v) 
{ 
    __node_pointer __nd = __root(); 
    if (__nd != nullptr) 
    { 
        while (true) 
        { 
            if (value_comp()(__v, __nd->__value_)) 
            { 
                if (__nd->__left_ != nullptr) 
                    __nd = static_cast<__node_pointer>(__nd->__left_); 
                else 
                { 
                    __parent = static_cast<__parent_pointer>(__nd); 
                    return __parent->__left_; 
                } 
            } 
            else 
            { 
                if (__nd->__right_ != nullptr) 
                    __nd = static_cast<__node_pointer>(__nd->__right_); 
                else 
                { 
                    __parent = static_cast<__parent_pointer>(__nd); 
                    return __nd->__right_; 
                } 
            } 
        } 
    } 
    __parent = static_cast<__parent_pointer>(__end_node()); 
    return __parent->__left_; 
} 
 
// Find leaf place to insert closest to __hint 
// First check prior to __hint. 
// Next check after __hint. 
// Next do O(log N) search. 
// Set __parent to parent of null leaf 
// Return reference to null leaf 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
__tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint, 
                                               __parent_pointer& __parent, 
                                               const key_type& __v) 
{ 
    if (__hint == end() || !value_comp()(*__hint, __v))  // check before 
    { 
        // __v <= *__hint 
        const_iterator __prior = __hint; 
        if (__prior == begin() || !value_comp()(__v, *--__prior)) 
        { 
            // *prev(__hint) <= __v <= *__hint 
            if (__hint.__ptr_->__left_ == nullptr) 
            { 
                __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
                return __parent->__left_; 
            } 
            else 
            { 
                __parent = static_cast<__parent_pointer>(__prior.__ptr_); 
                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_; 
            } 
        } 
        // __v < *prev(__hint) 
        return __find_leaf_high(__parent, __v); 
    } 
    // else __v > *__hint 
    return __find_leaf_low(__parent, __v); 
} 
 
// Find place to insert if __v doesn't exist 
// Set __parent to parent of null leaf 
// Return reference to null leaf 
// If __v exists, set parent to node of __v and return reference to node of __v 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
__tree<_Tp, _Compare, _Allocator>::__find_equal(__parent_pointer& __parent, 
                                                const _Key& __v) 
{ 
    __node_pointer __nd = __root(); 
    __node_base_pointer* __nd_ptr = __root_ptr(); 
    if (__nd != nullptr) 
    { 
        while (true) 
        { 
            if (value_comp()(__v, __nd->__value_)) 
            { 
                if (__nd->__left_ != nullptr) { 
                    __nd_ptr = _VSTD::addressof(__nd->__left_); 
                    __nd = static_cast<__node_pointer>(__nd->__left_); 
                } else { 
                    __parent = static_cast<__parent_pointer>(__nd); 
                    return __parent->__left_; 
                } 
            } 
            else if (value_comp()(__nd->__value_, __v)) 
            { 
                if (__nd->__right_ != nullptr) { 
                    __nd_ptr = _VSTD::addressof(__nd->__right_); 
                    __nd = static_cast<__node_pointer>(__nd->__right_); 
                } else { 
                    __parent = static_cast<__parent_pointer>(__nd); 
                    return __nd->__right_; 
                } 
            } 
            else 
            { 
                __parent = static_cast<__parent_pointer>(__nd); 
                return *__nd_ptr; 
            } 
        } 
    } 
    __parent = static_cast<__parent_pointer>(__end_node()); 
    return __parent->__left_; 
} 
 
// Find place to insert if __v doesn't exist 
// First check prior to __hint. 
// Next check after __hint. 
// Next do O(log N) search. 
// Set __parent to parent of null leaf 
// Return reference to null leaf 
// If __v exists, set parent to node of __v and return reference to node of __v 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint, 
                                                __parent_pointer& __parent, 
                                                __node_base_pointer& __dummy, 
                                                const _Key& __v) 
{ 
    if (__hint == end() || value_comp()(__v, *__hint))  // check before 
    { 
        // __v < *__hint 
        const_iterator __prior = __hint; 
        if (__prior == begin() || value_comp()(*--__prior, __v)) 
        { 
            // *prev(__hint) < __v < *__hint 
            if (__hint.__ptr_->__left_ == nullptr) 
            { 
                __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
                return __parent->__left_; 
            } 
            else 
            { 
                __parent = static_cast<__parent_pointer>(__prior.__ptr_); 
                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_; 
            } 
        } 
        // __v <= *prev(__hint) 
        return __find_equal(__parent, __v); 
    } 
    else if (value_comp()(*__hint, __v))  // check after 
    { 
        // *__hint < __v 
        const_iterator __next = _VSTD::next(__hint); 
        if (__next == end() || value_comp()(__v, *__next)) 
        { 
            // *__hint < __v < *_VSTD::next(__hint) 
            if (__hint.__get_np()->__right_ == nullptr) 
            { 
                __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
                return static_cast<__node_base_pointer>(__hint.__ptr_)->__right_; 
            } 
            else 
            { 
                __parent = static_cast<__parent_pointer>(__next.__ptr_); 
                return __parent->__left_; 
            } 
        } 
        // *next(__hint) <= __v 
        return __find_equal(__parent, __v); 
    } 
    // else __v == *__hint 
    __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
    __dummy = static_cast<__node_base_pointer>(__hint.__ptr_); 
    return __dummy; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
void __tree<_Tp, _Compare, _Allocator>::__insert_node_at(
    __parent_pointer __parent, __node_base_pointer& __child,
    __node_base_pointer __new_node) _NOEXCEPT
{ 
    __new_node->__left_   = nullptr; 
    __new_node->__right_  = nullptr; 
    __new_node->__parent_ = __parent; 
    // __new_node->__is_black_ is initialized in __tree_balance_after_insert 
    __child = __new_node; 
    if (__begin_node()->__left_ != nullptr) 
        __begin_node() = static_cast<__iter_pointer>(__begin_node()->__left_); 
    _VSTD::__tree_balance_after_insert(__end_node()->__left_, __child); 
    ++size(); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key, class... _Args> 
pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
__tree<_Tp, _Compare, _Allocator>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args) 
{ 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_equal(__parent, __k); 
    __node_pointer __r = static_cast<__node_pointer>(__child); 
    bool __inserted = false; 
    if (__child == nullptr) 
    { 
        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
        __r = __h.release(); 
        __inserted = true; 
    } 
    return pair<iterator, bool>(iterator(__r), __inserted); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key, class... _Args> 
pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args( 
    const_iterator __p, _Key const& __k, _Args&&... __args) 
{ 
    __parent_pointer __parent; 
    __node_base_pointer __dummy; 
    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __k); 
    __node_pointer __r = static_cast<__node_pointer>(__child); 
    bool __inserted = false; 
    if (__child == nullptr) 
    { 
        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
        __r = __h.release(); 
        __inserted = true; 
    } 
    return pair<iterator, bool>(iterator(__r), __inserted); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class ..._Args> 
typename __tree<_Tp, _Compare, _Allocator>::__node_holder 
__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&& ...__args) 
{ 
    static_assert(!__is_tree_value_type<_Args...>::value, 
                  "Cannot construct from __value_type"); 
    __node_allocator& __na = __node_alloc(); 
    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); 
    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...); 
    __h.get_deleter().__value_constructed = true; 
    return __h; 
} 
 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class... _Args> 
pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
__tree<_Tp, _Compare, _Allocator>::__emplace_unique_impl(_Args&&... __args) 
{ 
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_equal(__parent, __h->__value_); 
    __node_pointer __r = static_cast<__node_pointer>(__child); 
    bool __inserted = false; 
    if (__child == nullptr) 
    { 
        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
        __r = __h.release(); 
        __inserted = true; 
    } 
    return pair<iterator, bool>(iterator(__r), __inserted); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class... _Args> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_impl(const_iterator __p, _Args&&... __args) 
{ 
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
    __parent_pointer __parent; 
    __node_base_pointer __dummy; 
    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __h->__value_); 
    __node_pointer __r = static_cast<__node_pointer>(__child); 
    if (__child == nullptr) 
    { 
        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
        __r = __h.release(); 
    } 
    return iterator(__r); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class... _Args> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args) 
{ 
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__h->__value_)); 
    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
    return iterator(static_cast<__node_pointer>(__h.release())); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class... _Args> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p, 
                                                        _Args&&... __args) 
{ 
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__h->__value_)); 
    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
    return iterator(static_cast<__node_pointer>(__h.release())); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
__tree<_Tp, _Compare, _Allocator>::__node_assign_unique(const __container_value_type& __v, __node_pointer __nd) 
{ 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_equal(__parent, _NodeTypes::__get_key(__v)); 
    __node_pointer __r = static_cast<__node_pointer>(__child); 
    bool __inserted = false; 
    if (__child == nullptr) 
    { 
        __nd->__value_ = __v; 
        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd)); 
        __r = __nd; 
        __inserted = true; 
    } 
    return pair<iterator, bool>(iterator(__r), __inserted); 
} 
 
 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd) 
{ 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__nd->__value_)); 
    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd)); 
    return iterator(__nd); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p, 
                                                       __node_pointer __nd) 
{ 
    __parent_pointer __parent; 
    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__nd->__value_)); 
    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd)); 
    return iterator(__nd); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__remove_node_pointer(__node_pointer __ptr) _NOEXCEPT
{ 
    iterator __r(__ptr);
    ++__r; 
    if (__begin_node() == __ptr)
        __begin_node() = __r.__ptr_; 
    --size(); 
    _VSTD::__tree_remove(__end_node()->__left_, 
                         static_cast<__node_base_pointer>(__ptr));
    return __r;
}

#if _LIBCPP_STD_VER > 14
template <class _Tp, class _Compare, class _Allocator>
template <class _NodeHandle, class _InsertReturnType>
_LIBCPP_INLINE_VISIBILITY
_InsertReturnType
__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
    _NodeHandle&& __nh)
{
    if (__nh.empty())
        return _InsertReturnType{end(), false, _NodeHandle()};

    __node_pointer __ptr = __nh.__ptr_;
    __parent_pointer __parent;
    __node_base_pointer& __child = __find_equal(__parent,
                                                __ptr->__value_);
    if (__child != nullptr)
        return _InsertReturnType{
            iterator(static_cast<__node_pointer>(__child)),
            false, _VSTD::move(__nh)};

    __insert_node_at(__parent, __child,
                     static_cast<__node_base_pointer>(__ptr));
    __nh.__release_ptr(); 
    return _InsertReturnType{iterator(__ptr), true, _NodeHandle()};
}

template <class _Tp, class _Compare, class _Allocator>
template <class _NodeHandle>
_LIBCPP_INLINE_VISIBILITY
typename __tree<_Tp, _Compare, _Allocator>::iterator
__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
    const_iterator __hint, _NodeHandle&& __nh)
{
    if (__nh.empty())
        return end();

    __node_pointer __ptr = __nh.__ptr_;
    __parent_pointer __parent;
    __node_base_pointer __dummy;
    __node_base_pointer& __child = __find_equal(__hint, __parent, __dummy,
                                                __ptr->__value_);
    __node_pointer __r = static_cast<__node_pointer>(__child);
    if (__child == nullptr)
    {
        __insert_node_at(__parent, __child,
                         static_cast<__node_base_pointer>(__ptr));
        __r = __ptr;
        __nh.__release_ptr(); 
    }
    return iterator(__r);
}

template <class _Tp, class _Compare, class _Allocator>
template <class _NodeHandle>
_LIBCPP_INLINE_VISIBILITY
_NodeHandle
__tree<_Tp, _Compare, _Allocator>::__node_handle_extract(key_type const& __key)
{
    iterator __it = find(__key);
    if (__it == end())
        return _NodeHandle();
    return __node_handle_extract<_NodeHandle>(__it);
}

template <class _Tp, class _Compare, class _Allocator>
template <class _NodeHandle>
_LIBCPP_INLINE_VISIBILITY
_NodeHandle
__tree<_Tp, _Compare, _Allocator>::__node_handle_extract(const_iterator __p)
{
    __node_pointer __np = __p.__get_np();
    __remove_node_pointer(__np);
    return _NodeHandle(__np, __alloc());
}

template <class _Tp, class _Compare, class _Allocator>
template <class _Tree>
_LIBCPP_INLINE_VISIBILITY
void
__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_unique(_Tree& __source)
{
    static_assert(is_same<typename _Tree::__node_pointer, __node_pointer>::value, "");

    for (typename _Tree::iterator __i = __source.begin();
         __i != __source.end();)
    {
        __node_pointer __src_ptr = __i.__get_np();
        __parent_pointer __parent;
        __node_base_pointer& __child =
            __find_equal(__parent, _NodeTypes::__get_key(__src_ptr->__value_));
        ++__i;
        if (__child != nullptr)
            continue;
        __source.__remove_node_pointer(__src_ptr);
        __insert_node_at(__parent, __child,
                         static_cast<__node_base_pointer>(__src_ptr));
    }
}

template <class _Tp, class _Compare, class _Allocator>
template <class _NodeHandle>
_LIBCPP_INLINE_VISIBILITY
typename __tree<_Tp, _Compare, _Allocator>::iterator
__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(_NodeHandle&& __nh)
{
    if (__nh.empty())
        return end();
    __node_pointer __ptr = __nh.__ptr_;
    __parent_pointer __parent;
    __node_base_pointer& __child = __find_leaf_high(
        __parent, _NodeTypes::__get_key(__ptr->__value_));
    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
    __nh.__release_ptr(); 
    return iterator(__ptr);
}

template <class _Tp, class _Compare, class _Allocator>
template <class _NodeHandle>
_LIBCPP_INLINE_VISIBILITY
typename __tree<_Tp, _Compare, _Allocator>::iterator
__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(
    const_iterator __hint, _NodeHandle&& __nh)
{
    if (__nh.empty())
        return end();

    __node_pointer __ptr = __nh.__ptr_;
    __parent_pointer __parent;
    __node_base_pointer& __child = __find_leaf(__hint, __parent,
                                               _NodeTypes::__get_key(__ptr->__value_));
    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
    __nh.__release_ptr(); 
    return iterator(__ptr);
}

template <class _Tp, class _Compare, class _Allocator>
template <class _Tree>
_LIBCPP_INLINE_VISIBILITY
void
__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_multi(_Tree& __source)
{
    static_assert(is_same<typename _Tree::__node_pointer, __node_pointer>::value, "");

    for (typename _Tree::iterator __i = __source.begin();
         __i != __source.end();)
    {
        __node_pointer __src_ptr = __i.__get_np();
        __parent_pointer __parent;
        __node_base_pointer& __child = __find_leaf_high(
            __parent, _NodeTypes::__get_key(__src_ptr->__value_));
        ++__i;
        __source.__remove_node_pointer(__src_ptr);
        __insert_node_at(__parent, __child,
                         static_cast<__node_base_pointer>(__src_ptr));
    }
}

#endif // _LIBCPP_STD_VER > 14 

template <class _Tp, class _Compare, class _Allocator>
typename __tree<_Tp, _Compare, _Allocator>::iterator
__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p)
{
    __node_pointer __np = __p.__get_np();
    iterator __r = __remove_node_pointer(__np);
    __node_allocator& __na = __node_alloc(); 
    __node_traits::destroy(__na, _NodeTypes::__get_ptr( 
        const_cast<__node_value_type&>(*__p))); 
    __node_traits::deallocate(__na, __np, 1); 
    return __r; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l) 
{ 
    while (__f != __l) 
        __f = erase(__f); 
    return iterator(__l.__ptr_); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::size_type 
__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k) 
{ 
    iterator __i = find(__k); 
    if (__i == end()) 
        return 0; 
    erase(__i); 
    return 1; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::size_type 
__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k) 
{ 
    pair<iterator, iterator> __p = __equal_range_multi(__k); 
    size_type __r = 0; 
    for (; __p.first != __p.second; ++__r) 
        __p.first = erase(__p.first); 
    return __r; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) 
{ 
    iterator __p = __lower_bound(__v, __root(), __end_node()); 
    if (__p != end() && !value_comp()(__v, *__p)) 
        return __p; 
    return end(); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::const_iterator 
__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) const 
{ 
    const_iterator __p = __lower_bound(__v, __root(), __end_node()); 
    if (__p != end() && !value_comp()(__v, *__p)) 
        return __p; 
    return end(); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::size_type 
__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const 
{ 
    __node_pointer __rt = __root(); 
    while (__rt != nullptr) 
    { 
        if (value_comp()(__k, __rt->__value_)) 
        { 
            __rt = static_cast<__node_pointer>(__rt->__left_); 
        } 
        else if (value_comp()(__rt->__value_, __k)) 
            __rt = static_cast<__node_pointer>(__rt->__right_); 
        else 
            return 1; 
    } 
    return 0; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::size_type 
__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const 
{ 
    __iter_pointer __result = __end_node(); 
    __node_pointer __rt = __root(); 
    while (__rt != nullptr) 
    { 
        if (value_comp()(__k, __rt->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__rt); 
            __rt = static_cast<__node_pointer>(__rt->__left_); 
        } 
        else if (value_comp()(__rt->__value_, __k)) 
            __rt = static_cast<__node_pointer>(__rt->__right_); 
        else 
            return _VSTD::distance( 
                __lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)), 
                __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result) 
            ); 
    } 
    return 0; 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v, 
                                                 __node_pointer __root, 
                                                 __iter_pointer __result) 
{ 
    while (__root != nullptr) 
    { 
        if (!value_comp()(__root->__value_, __v)) 
        { 
            __result = static_cast<__iter_pointer>(__root); 
            __root = static_cast<__node_pointer>(__root->__left_); 
        } 
        else 
            __root = static_cast<__node_pointer>(__root->__right_); 
    } 
    return iterator(__result); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::const_iterator 
__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v, 
                                                 __node_pointer __root, 
                                                 __iter_pointer __result) const 
{ 
    while (__root != nullptr) 
    { 
        if (!value_comp()(__root->__value_, __v)) 
        { 
            __result = static_cast<__iter_pointer>(__root); 
            __root = static_cast<__node_pointer>(__root->__left_); 
        } 
        else 
            __root = static_cast<__node_pointer>(__root->__right_); 
    } 
    return const_iterator(__result); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::iterator 
__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v, 
                                                 __node_pointer __root, 
                                                 __iter_pointer __result) 
{ 
    while (__root != nullptr) 
    { 
        if (value_comp()(__v, __root->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__root); 
            __root = static_cast<__node_pointer>(__root->__left_); 
        } 
        else 
            __root = static_cast<__node_pointer>(__root->__right_); 
    } 
    return iterator(__result); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
typename __tree<_Tp, _Compare, _Allocator>::const_iterator 
__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v, 
                                                 __node_pointer __root, 
                                                 __iter_pointer __result) const 
{ 
    while (__root != nullptr) 
    { 
        if (value_comp()(__v, __root->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__root); 
            __root = static_cast<__node_pointer>(__root->__left_); 
        } 
        else 
            __root = static_cast<__node_pointer>(__root->__right_); 
    } 
    return const_iterator(__result); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, 
     typename __tree<_Tp, _Compare, _Allocator>::iterator> 
__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) 
{ 
    typedef pair<iterator, iterator> _Pp; 
    __iter_pointer __result = __end_node(); 
    __node_pointer __rt = __root(); 
    while (__rt != nullptr) 
    { 
        if (value_comp()(__k, __rt->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__rt); 
            __rt = static_cast<__node_pointer>(__rt->__left_); 
        } 
        else if (value_comp()(__rt->__value_, __k)) 
            __rt = static_cast<__node_pointer>(__rt->__right_); 
        else 
            return _Pp(iterator(__rt), 
                      iterator( 
                          __rt->__right_ != nullptr ? 
                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_)) 
                            : __result)); 
    } 
    return _Pp(iterator(__result), iterator(__result)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator, 
     typename __tree<_Tp, _Compare, _Allocator>::const_iterator> 
__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const 
{ 
    typedef pair<const_iterator, const_iterator> _Pp; 
    __iter_pointer __result = __end_node(); 
    __node_pointer __rt = __root(); 
    while (__rt != nullptr) 
    { 
        if (value_comp()(__k, __rt->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__rt); 
            __rt = static_cast<__node_pointer>(__rt->__left_); 
        } 
        else if (value_comp()(__rt->__value_, __k)) 
            __rt = static_cast<__node_pointer>(__rt->__right_); 
        else 
            return _Pp(const_iterator(__rt), 
                      const_iterator( 
                          __rt->__right_ != nullptr ? 
                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_)) 
                            : __result)); 
    } 
    return _Pp(const_iterator(__result), const_iterator(__result)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, 
     typename __tree<_Tp, _Compare, _Allocator>::iterator> 
__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) 
{ 
    typedef pair<iterator, iterator> _Pp; 
    __iter_pointer __result = __end_node(); 
    __node_pointer __rt = __root(); 
    while (__rt != nullptr) 
    { 
        if (value_comp()(__k, __rt->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__rt); 
            __rt = static_cast<__node_pointer>(__rt->__left_); 
        } 
        else if (value_comp()(__rt->__value_, __k)) 
            __rt = static_cast<__node_pointer>(__rt->__right_); 
        else 
            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)), 
                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)); 
    } 
    return _Pp(iterator(__result), iterator(__result)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
template <class _Key> 
pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator, 
     typename __tree<_Tp, _Compare, _Allocator>::const_iterator> 
__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const 
{ 
    typedef pair<const_iterator, const_iterator> _Pp; 
    __iter_pointer __result = __end_node(); 
    __node_pointer __rt = __root(); 
    while (__rt != nullptr) 
    { 
        if (value_comp()(__k, __rt->__value_)) 
        { 
            __result = static_cast<__iter_pointer>(__rt); 
            __rt = static_cast<__node_pointer>(__rt->__left_); 
        } 
        else if (value_comp()(__rt->__value_, __k)) 
            __rt = static_cast<__node_pointer>(__rt->__right_); 
        else 
            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)), 
                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)); 
    } 
    return _Pp(const_iterator(__result), const_iterator(__result)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
typename __tree<_Tp, _Compare, _Allocator>::__node_holder 
__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT 
{ 
    __node_pointer __np = __p.__get_np(); 
    if (__begin_node() == __p.__ptr_) 
    { 
        if (__np->__right_ != nullptr) 
            __begin_node() = static_cast<__iter_pointer>(__np->__right_); 
        else 
            __begin_node() = static_cast<__iter_pointer>(__np->__parent_); 
    } 
    --size(); 
    _VSTD::__tree_remove(__end_node()->__left_, 
                         static_cast<__node_base_pointer>(__np));
    return __node_holder(__np, _Dp(__node_alloc(), true)); 
} 
 
template <class _Tp, class _Compare, class _Allocator> 
inline _LIBCPP_INLINE_VISIBILITY 
void 
swap(__tree<_Tp, _Compare, _Allocator>& __x, 
     __tree<_Tp, _Compare, _Allocator>& __y) 
    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) 
{ 
    __x.swap(__y); 
} 
 
_LIBCPP_END_NAMESPACE_STD 
 
_LIBCPP_POP_MACROS 
 
#endif // _LIBCPP___TREE